Canning is a preservation method, where foods are packed in glass jars and immersed in either a waterbath or pressure canner and heated for a specific amount of time at a certain temperature. The type of food will dictate what type of canner must be used, temperature maintained and the process period that is required.

Processing foods such as fish or meats in metal tins is also a form of home canning, but it requires specialized equipment to apply and seal the metal lids to canning tins. It is more difficult to obtain information or supplies and equipment sources for this type of canning and it is therefore not as popular as canning with jars.

Maintaining heat and pressure during the canning process prevents harmful organism and bacterias from causing food spoilage and health concerns. When the canning time period has expired and it is safe to remove jars, during the cooling-off period, a vacuum is formed causing air to escape from the jars to form a safe airtight sealing of jar contents. This further protects the canned foods from bacterial growth, deterioration and spoilage.

In general, don't! Broken Chemistry glassware , in addition to having sharp and jagged edges which can seriously injure you, also have the added element of danger in that there is most likely chemical residue on the glass itself. Cutting yourself on a piece of broken glass with chemical residue on it could seriously mess things up, especially in an organic chemistry lab.

So if you have broken a piece of laboratory glass holding any chemicals -- a reaction, or simply a reagent waiting to be used -- alert your TA. Your TA will advise you in the proper method of cleaning up a chemical spill.

If you break a piece of glassware and chemicals are not involved, obtain a small dustpan and broom (there are a few sets in each teaching lab) and sweep up the pieces. Discard them in the 5-gallon white plastic bucket marked "BROKEN GLASS" in the lab. Do not handle broken glass by hand, if it can be avoided. Also, only place CLEAN broken glass in the "BROKEN GLASS" bucket. Broken glassware with chemical residue should either be cleaned (if there is a way to do so safely), or placed into the "LAB TRASH" bucket.

If you break a mercury thermometer, alert your TA and then come to the OCS window to request a mercury clean-up kit. Please do not throw the broken thermometers away in the general, lab, or glass trash! Place the thermometer in the mercury clean-up kit and return to the OCS. Broken thermometers result in mercury spills, which are toxic! Either your TA or OCS personnel will explain how to use the clean-up kit to clean up any spilled mercury from the thermometer. To safeguard against thermometer breakage and mercury spills, handle thermometers very carefully, do not use them as stirring rods, and always store them in their protective plastic casing.